SEATTLE, April 10 (Reuters) - Boeing Co hired Norsk Titanium AS to print the first structural titanium parts for its 787 Dreamliner, the Norwegian 3-D printing company said on Monday, paving the way to cost savings of $2 million to $3 million for each plane.

The contract is a major step in Boeing's effort to cut the cost of its barely profitable 787 and a sign of growing industrial acceptance of 3-D printing technology, which is replacing more expensive traditional ways of manufacturing components.

Strong, lightweight titanium alloy is seven times more costly than aluminum, and accounts for about $17 million of the cost of a $265 million Dreamliner, industry sources say.

Boeing has been trying to reduce the cost of titanium on the 787, which requires more of the metal than other models because of its carbon-fiber composite fuselage and wings. Titanium also is used extensively on Airbus Group SE's carbon-fiber A350.

"This means $2 million to $3 million in savings for each Dreamliner, at least," starting in 2018, Chip Yates, Norsk Titanium's vice president of marketing, said in a telephone interview.

Norsk worked with Boeing for more than a year to design four 787 parts and obtain Federal Aviation Administration certification for them.

Norsk expects the U.S. regulatory agency will approve the material properties and production process for the parts later this year, which would "open up the floodgates" and allow Norsk to print thousands of different parts for each Dreamliner, without each part requiring separate FAA approval, Yates said.

"You're talking about tons, literally," on the 787 that would be printed instead of made with traditional, expensive forging and machining, he said. (Reporting by Alwyn Scott; Editing by Jonathan Oatis)